Carburetor choke valve control



Patented l, l

meteor onnn'ron onoxn verlvn oon'rnor.

Kenneth Ht. Blake and Robert H. i Anderson, Ind., assignors to Bendix Aviation Corporation, South literal, Ind., a corporation of Delaware- Alml cation February 23, 1932, Serial No. 594,708

10 Cl. (or. 123179) invention relates to carburetors, and more particularly to mechanism for actuating the choke valve of a carburetor in accordance with temperature and other conditions developed by the operation of the engine with which the carburetor is associated. I

object of the invention is to provide mechv w for actuating the choke valve in accordance with temperature and engine speed.

A further object of the invention is to provide race for actuating the choke valve in accordance with starting conditions.

A further object of the invention is to provide mec for actuating the choke valve inaccore with temperature, manifold suction, and starting conditions, or any one or two of these factors.

Further objects and advantages of the invention will be apparent from the following description, taken in connection with the appended wing, in which:

1 is an assembly view of an engine having associated therewith a device embodying the invention; and

a 2 1 w 2 is an enlarged view of the choke-actua mechanism, partly in section, and showing the electrical connections diagrammatically.

e engine to which the invention is applied y be of any preferred type, and is shown as comprising a block 10, exhaust manifold 12 and in old 14. A carburetor 16 is connected to the intake manifold, and may be of any prefe type. It comprises an air born 18 having mounted therein the usual choke valve 20 rotaly mounted on a shaft 22 and preferably provided with a pressure actuated auxiliary valve 23. A control arm 24 is fixed to shaft 22 and is provided at its free end with a slot 26 which receives the upper end of an actuating rod 28.

h solenoid 30 is positioned adjacent the air horn and is connected in the starter circuit 32 by controlled starter switch 33. Circuit 32 is connected .to the generator 34 of the car and to the storage battery 35 in the usual manner. The core at of the solenoid has an extension 38 having a bore which receives the lower end of rod 28 in telescoping relation. A cage 40 formed on extension it retains a compression spring 42 which bears against a stop M fixed to red 28 to urge the rod downwardly and the core upwardly relative to each other to form an over connection between members 2% and 33 which yields under tension.

The core 36 has a lower extension 46 which is any writable means to a flexible diaphragm 48 enclosed in a casing 50 and urged up wardly by a spring 52. The casing is connected, by tubing 54, to the fuel line leading from fuel pump 56 to the carburetor, so that the pressure on diaphragm 48 will vary with the speed of the e.

Rod 28 has a spur .58 which engages a slot in a rod fixed to the movable end of a temperature-expansive member or sylphon 62 which is disposed at any portion of the engine which is subjected to varying temperatures incident'to the operation of the engine.

The operation of the device is as follows. When the engineis at rest and cold, rod 28 and the parts connected thereto are at their lowermost positions, being moved thereto by gravity, and valve 20 is in its closed position indicated at 21'. If new switch 33 is closed to actuate the starter, solenoid 30 will exert a downward force on core 36, but this will have no effect since the core is already in its lowermost position. The fuel pressure in casing 50 developed by cranking is not suflicient to materially raise diaphragm 48, and hence the choke valve remains substantially closed, the only air supplied to the carburetor being that passing through auxiliary valve 23.

When the engine begins to fire, switch 33 is of course opened, and the fuel pressure rises sufficiently to move diaphragm 48 and rod 28 upwardly, thus partially opening valve 20. The valve 20 is not fully opened, however, because the spur 58 is in contact with the upper end of slot 60 which exerts a downward pressure thereupon due to the fact that sylphon 62 is in its collapsed position. As the engine warms up, sylphon 62 gradually expands, permitting spur 58 to move upwardly under the influence of the variable force exerted upon diaphragm 48 by the fuel, which proportions the air intake to the needs of the engine by opening the choke valve farther when the engine speeds up and partially closing it when the engine speed decreases.

If the starter is actuated while the engine is still warm from previous operation or due to warm weather, solenoid 30 will move choke 20 nearly or completely to its fully closed position by compressing the springs 4.2 and 52 and to some extent sylphon 62, the resultant position of the choke being dependent upon the stifiness of springs 42 and 52 relative to sylphon 62.

Although the invention has been described with particular reference to a specific embodiment, it is not limited to such embodiment but may be embodied in other forms witmn the scope of the following We claim:

1. In an internal combustion engine, a carburetor, a choke valve in the carburetor, means including a flexible diaphragm responsive to fuel pressure for yieldingly controlling the choke valve and temperature responsive means for modifying the action of the pressure responsive means.

2.'In an internal combustion engine having a fuel pump and a carburetor provided with a balanced choke valve; means responsive to pressures developed during the operation of the fuel pump for modifying the action of the choke valve, and electrical means including a solenoid having a movable part for modifying the action of the aforesaid means.

3. In an internal combustion engine having a carburetor, a choke valve for the carburetor, and

means for supplying fuel under pressure to the carburetor; means including a chamber having a movable wall responsive to fuel pressure operably connected by a yielding connection for controlling the choke valve.

4. In an internal combustion engine having a carburetor, a choke valve for the carburetor, and means for supplying fuel under pressure to the carburetor; temperature responsive means for controlling the choke valve, and means responsive to fuel pressure including a flexible diaphragm operably connected to the choke valve for modifying the temperature responsive means.

5. In an internal combustion engine having a carburetor, a choke valve for the carbureto, a source of fluid pressure, temperature responsive means comprising a flexible bellows for controlling the choke valve, fluid pressure responsive means including a chamber having a movable wall for modifying the temperature responsive means, and means operative only upon starting the engine for modifying the two first mentioned means.

6. In an internal combustion engine having a carburetor, a choke valve therefor, a fuel pump, and a starter; temperature responsive means for controlling the choke valve, fuel pressure responsive means including a diaphragm for modifying the temperature responsive means, and starter actuated electro-magnetic means including a solenoid having a movable part for modifying the action of the other means.

7. In combination with an internal combustion engine having a carburetor, a choke valve in the carburetor, a fluid pump, an electric starter, temperature responsive means to control the choke valve, a chamber having a movable wall subjected to pressure developed by the fluid pump, a solenoid having a movable member operable by the electric starter, a member yieldingly connected to the choke valve and jointly controlled by the temperature responsive means, the fluid pressure responsive means, and the movable member of the solenoid to actuate the choke valve.

8. In combination with an internal combustion engine having a carburetor, a fuel pump, and an electric starter, a choke valve in the carburetor, and control means for said choke valve comprising electromagnetic means energized upon closing of the starter circuit, a diaphragm actuated by pressure generated by the fuel pump, and a temperature-responsive bellows, said electromagnetic means and diaphragm being connected to the choke valve by a yielding connection.

9. men internal combustion engine, a carburetor, a choke valve in the carburetor, a fuel pump, an electric starter, control means for the choke valve comprising a solenoid having a movable member energized when the electric starter is actuated, a diaphragm subjected to the pressure developed by the fuel pump, and means connecting said movable member and diaphragm to the choke valve.

10. In an internal combustion engine, a carburetor, a choke valve in the carburetor, a fuel pump, an electric starter, control means for the choke valve comprising a solenoid having a movable member energized when the electric starter is actuated. a diaphragm subjected to the pressure developed by the fuel pump, yielding means connecting said movable member and diaphragm to the choke valve, and temperature responsive means operable to modify the movement of the choke valve.

KENNETH R. BLAKE. ROBERT H. HILL. 

